Shared games and videos fill a phone held sideways

On a phone, turning a shared game or video sideways now fills the screen with it, over the site's header and menu, with a button to leave. A full-screen button does the same on any device, and held upright, a game's controls fit on the screen without scrolling. The assistant bubble steps aside instead of covering the controls, and a shared canvas no longer shows its internal version name as its title.